Libraries contain vast amounts of information that create possibilities, and stories, that have an immense amount of narrative weight and power. They are basically one giant liminal space, but one that exists for the people that use it. And it's the people that work in the library that create that connection.
The Fair Folk have opinions about librarians. There's a certain amount of idealism involved that would make them vulnerable, but so much of what they know and do is dangerous. They are accorded a certain not-inconsiderable amount of respect and caution, let's say, and leave it at that.
There are two kinds of librarians at Elsewhere University, two sides to the same coin. There are the librarians who have an employee ID number, and a title on their nametag. They have lunch breaks, vacation time, and salt and iron in their pockets and stashed in odd corners in their desk drawers and offices, just like the rest of the staff and faculty. And then there are The Other Librarians. The other librarians can be found on floors ten through twenty-three. Officially, there are nine floors to the library. (This does not include the rooftop garden that is not accessible by stairwell or elevator.) The sub-basements are officially recognized. The tunnels are not.
The other librarians also have officially-issued library nametags. All they say is "librarian." Some of the other librarians may have been human once. They may have officially retired. They may have learned too much, or willingly given up something that held them tethered to mundane cares outside of The Library, or made a bargain for something the library needed.
There are stories of a cataloguer, best of his generation, who reached a point where he could recite chapter and verse of the standards, never misjudged a subject heading or used the wrong cutter number. The arcanest of arcane inscriptions held still for him while he captured the true author and all relevant cross-references. There was not a text he could not read, or element of biliographic control that he could not master. The years went by, and the standards changed, Anglo American Cataloging Rules superceded the Rules for Descriptive Cataloging, ISBNs were introduced, AACR became AACR2, and a switch from cards to computer records loomed large. He knew so much, but was afraid so little of it would still be relevant. He made a deal.
He wasn't the first. There are still cards appearing in the card catalogue today written in copperplate Library Hand script, as proscribed by Melville Dewey, with a pen and an inkwell.
There are still memories on the lower floors of a reference librarian who could find anything. There are people on staff who worked side-by-side with her on late night reference desk shifts, and tell stories of how she had an infinite command of Boolean logic to wring every penny out of the paid-by-the-second online search services. There was not an annotated bibliography or index that she didn't have at her fingertips, and she could walk a student though the reference interview from "I need a book, I guess" to "help me find three print sources for my introduction to pre-confederate Canadian literature mid-term paper" in twenty seconds with a smile. Rumour has it that she bargained away the memory of every childhood pet she ever had to get internet access in the library for undergraduates. Officially, she retired in the late nineties. But in the Deep Library, there are those who can coax the dial-up modem into connecting to a Dialog subscription that the university hasn't paid for in two decades, and bring back an answer in seconds every time.
There are fading echoes of the year that the entire cataloguing department and half the reference librarians vanished in the stacks in the early 1940's. The university was smaller then, and the protections that were needed to balance a tumultuous time in world history took a terrible toll. It was said that if you stood in certain parts of the stacks, you could hear the air raid sirens, and watch the collection grow as refugee books were taken in. There were dark whispers that some of the staff disappeared into the library in a trade for safety for family members or one of the other desperate bargains made in wartime, but some were promoted to the upper floors without warning because the library didn't want to lose their valuable talents to conscription or worse.
If the Library needs you, it will take you. If you are lucky, it will be on your terms, at a time of your choosing. In most cases, a masters' degree in library and information sciences from a nationally-certified graduate program is required, though in some rare cases, an equivalent combination of education and experience may be considered.
Most undergraduates and visitors (both the mundane kind that come from outside the campus, and the Visitors), and some university support staff, will leave with a vague impression of any of the librarians as an ominous yet helpful shape, and an overwhelming sense of sameness. This is a type of protective camouflage that the library generates, and it extends to cover all the librarians, the one that leave at the end of the day, and the ones that do not. They cannot all be the same. It is, of course, impossible to run a library without a wide and varied pool of skill sets and personalities, all of which contribute to the, shall we say, unique personalities, egos, interdepartmental rivalries, feuds, and alliances that are the lifeblood of an academic library.
This protection waxes and wanes depending on the year. During the spring and summer semesters following the Chemistry Majors' Revolt, anyone remotely associated with any of the science departments would find themselves on the doorstep of the library with a ringing in their ears like the sudden absence of a loud noise, holding the books or other information they'd gone to the library to find, with no memory of how it got there. An entire spring-semester introductory chemistry class knows the structure of an APA-style bibliography inside and out, but could not tell you when or where they learned it.
In more recent times, sufficiently motivated undergrads, graduate students, and faculty will have little trouble differentiating one librarian from another, if they are on floors one through nine. (They must, of course, be referred to by job title as they do not have names.)
There are operational needs that must be met. It's hard to plead your case as to why the library really should keep that critical music theory database for your graduate level seminar course that currently costs as much as all of the journal subscriptions for the art history department combined when you're not sure if you're talking to the subject liaison librarian for fine arts, the head of interlibrary loans, or an eldritch creature with no face but a really excellent recall for geopolitical boundaries in medieval Africa, and a working knowledge of twelve dead languages, seven of which were never spoken by a human tongue.
(Interlibrary Loans and Fine Arts--the subject librarian, not the department--have been in the midst of a prolonged feud for the past decade over a hiring committee disagreement regarding practicum student placements and a botched exorcism. It is rivalled only by the cold war between Interlibrary Loans and Cataloguing over supply budgets that's been running since the late nineties. Confusing one for the other would be unhelpful, to say the least.)
The Other Librarians generally do not encroach on their colleagues' responsibilities. They are still librarians with all of the professional ethics that entails, and are generally orderly and rule-abiding, unless a fundamental principle of librarianship is at risk. (Do not speak of internet filtering within the library walls if you wish to leave with all of your fingers intact.) The Deep Library should be approached with utmost caution, regardless. Some people in the profession say, your library should have something in it to offend everyone. EU's library would agree to that statement, with some extensive additions, explanatory footnotes, and cautionary appendices. Respect the Library.